Kite



June 7, 1949. w s ow 2,472,137

' KITE Filed May 16, 1947 JNVENTOR.

zomaea N. W/MSZOW ig (97612; 75y

Patented June 7, 1949 UNITED S'EATES PATENT OFFECE 6 Claims.

My invention relates to improvements in kites and is more particularly concerned with kites designed to operate without an auxiliary tail balancing element.

The primary purposes of my invention are to provide a kite of extremely simple construction having no attachment between the frame members and possessed of improved flight characteristics. A secondary purpose is to provide a kite having a pyramidoidal planing surface and wherein the rigid longitudinal frame member serves also as a vertical stabilizing element projecting forwardly of the planing surface.

In the achievement of the purposes I have employed in my kite a transverse strut element adapted to extend the planing surface to the lee of the longitudinal member and being freely movable rearwardly relative to the longitudinal member. This transverse strut element in flight will be subject to stress in. compression on the ends rather than subject to a bending force on the ends against the center, as is the case in conventional kites of bent stick construction. The design of the invention embodying these features is such that the component elements may be very light, easily folded for packaging, quickly assembled for flight operations, and both efficient and durable as an airfoil.

To the accomplishment of the foregoing and related purposes, this invention, then, consists of the means hereinafter fully described and particularly pointed out in the claims; the annexed drawings and the following description setting forth in detail certain structures embodying the invention, said disclosed means constituting however, but one of various forms in which the principles of the invention may be used.

In the drawings:

Fig. 1 is a rear view in perspective of the assembled kite;

Fig. 2 is a plan view;

Fig. 3 is a side View taken on the line 3-3 of Fig. 2 and showing one form of flying harness; and

Fig. 4 is a plan view of the covering sheet before application to the frame members.

In Fig. 1 there is shown the structural outline of a preferred form of my invention. A flexible polygonal sheet If! of paper or other suitable material forms the planing surface. of the sheet l0 are folded over as at I l to provide a channel for a tensioned light string or filamentary element 12 which extends about the entire periphery of the sheet. The string I 2 is contained within the secured fold of the sheet The edges the thin frame member.

but is not necessarily attached thereto, at least not in such a way that it cannot move slidably in the channel. Although normally a string will be used extending about the edges of a light paper sheet for tensioning effect and strength, if a sheet of sufficient strength is employed, the string may be omitted.

The member I3 is a rigid longitudinal frame support for the sheet l2. This member I3 may vary in dimensions, depending upon the kite size desired and other factors, but for purposes of illustration may be in the nature of two inches in width and one-sixteenth of an inch in thickness when the overall length is about eighteen inches and the sheet width approximately equal to the length or somewhat less. The ends of the member l3 are notched as at Ma and 20a to engage the string l2 at the longitudinal extremities of the sheet. It will be noted that the notches Ila, 29a are located in the after or leeward portion of the end area of frame l3.

Over and upon a triangular area of the frame member l3, extending upwardly from the base It to a vertex at I5, a portion of the sheet 10, as indicated by the dotted lines It in Fig. 4, is secured with glue or other suitable means to form a triangular keel II. This member ll acts as a vertical stabilizer for the kite in flight. The frame member I3 is also tapered in depth rear- Wardly from the vertex l5 to the after area of the upper end 20. The frame member 13 thus provides a contactin longitudinal support for the sheet In throughout the length of its leading or windward edge Whereon the sheet is secured.

Since the member l3 should be light in Weight and yet sufficiently strong to have the rigidity needed effectively to serve as a frame support, I have folded a portion of the sheet l0 over a triangular area of the frame It for two purposes.

- One purpose is to form the keel H as mentioned above. The second purpose is to give additional rigidity to the thin frame member l3. When the sheet is folded over the frame and glued tightly thereto, certain stiffening is added to Further increased rigidity is imparted when the lateral extensions of the sheet forming the planing surface are stretched tight when the transverse strut structure described below is fitted into position. Because of this truss-like design, the thin frame member is able to resist normal bending movements.

To support the sides of the sheet Ill laterally of the longitudinal frame member is, there is provided a transversely extending strut structure 2|,

the outer ends of which are notched and adapted to engage the tensioned string I2 at the lateral extremities of the sheet. To give additional durability and strength to the kite, the exterior ends of the strut 21 may be fitted in pockets of the sheet adjacent the lateral extremities and may have the filamentary element wrapped about the ends of the strut and tied thereto. This strut structure may be a single element if desired, but, as shown, in the drawings, consists of two partially overlapping sticks 23 and 24.

On opposite sides of each stick there is provided a stop member 26. In assembly the interior end of each stick is disposed against the respective stop member of the other stick and the sticks are overlapped through aportion of their length.

To hold the sticks in overlapped position any suitable interlocking means may be employed, such as a sleeve, but "for convenience I have shown rubberbands -21 of small diameter which can .beslipped over the overlapped sticks as at Z8,.and.29 to. hold the sticks in position as a rigid transverse strut structure. Another expedient interIOckarrangement is to. place the sticks end to..end in abutting relationship without overlap and to hold them in this position with a sleeve.

.Itwill be noted that the transverse strut structure,2i isdisposed tothe lee of the longitudinal member l3'andis attached neither to the member .lftnor .tothe sheet lat any point other than at thelateral extremities of the sheet where the string i2 isengaged. Thus,. during flight, the strut .structureZl ,isfreely movable rearwardly relativato the longitudinal member.

.Whenthe kite ,is..assembled, the filamentary element or string, 1,2 will be attached at the lateral andlongitudinalextremities of thesheet .to the strut ,and ,frame member ,ends. The length .of the .strut structure, 2| .willbe suchthat a slight tension will be placed upon thestringliZ when the striltis .set in position. Because .of the rearward location ofthe notches Maand 2lla,.the string l'2 ,as.contained within the edge folds H will lie in approximately a single plane.

.For flight operations .a flying harness, as shoWninFig. ,3 at 3i, or a string attached to but onelpoint, ,can be attached to the longitudinal member 13. Thus,vin ,fiight, wind or .air forces upontheplaning surface will tend to force the lateral. corners of the sheet l rearwardly. Such movement willincrease the tension on string 12 and-tend. to tighten the'sheet edges.

.since thestrut member 2| .is not attached to frame ,I'3, any movement of the lateral extremities of .thesheet .ID rearwardly due to increased airpressure on the planing surface (or low pressure on theleeward side of the sheet) will subjectthe strut to stress in compression. Inkites of conventional design, cross-members have heretofore been either attached to the longitudinal-memberat .the .point of .intersection, or located windward of the longitudinalmember, or attached .tothe covering material of thekite.

In allthese designs air pressure onthe planing surfaceof the kite tends to exert abending movement on the cross-member of the ends against thecenternwhich thus loosens the tension on the edges of thecovering sheet, which in turn allows further bend n etc.

,I.have found that the feature of automatic self-adjustment of the tension upon the string I2 by rearward movement of the member 2| keeps the sheet I lltaut and thus permits smooth flow ofairt the ed e of the kite. Conventional kites '4 have an almost inevitable tendency to form concave pockets on the windward side of the covering sheet between the peripheral string and the frame members. These pockets reduce to a great extent the efiiciency of the airfoil and invite instability in flight characteristics.

This automatic adjustment in flight feature also helps the kite to have such buoyancy that its flying position approaches a vertical angle above the controller, with the appreciable deviation caused by wind drift of the kite, and its controlling string, and the weight of the string.

Referring now to the shape of the windward side of the sheet in when the kite is assembled for flight, it will be seen that the planing surface has a pyramidoidal appearance. In the embodiment shown in the drawings and windward surface of the kite will present four separate planes intersecting at the vertex [5 which will normally be located forwardly of the intersection of the longitudinal and transverse members.

Wind forces and thermal currents striking the planing surface of the kite will be split bythe heel or vertical stabilizer I! and diverted to the edges of the kite by the slanting surfaces of-the sheet. Thus effective fiyingbalance can Ibe obtained withoutresort .to auxiliary tail elements to reduce lateral diving tendencies usual in kites of conventional design.

Whiletherehas been-shown and describedw. four-sided kite, it will be understoodthat other shapes can beemployed within the scope of .the invention; .snch,.for example, as akite corresponding in shape to a conventional airplane viewed .in plan.

Othermodesof applying the principles of .my invention maybe employed instead of the .0116 explained, change being made as regards the structure herein disclosed, provided the means stated by any of the following claims orthe equivalent of such stated means be employed.

.Itherefore particularly point out anddistinctly claim as my invention:

.1. In akiteof thetype describeda polygonal flexible sheet, means for supporting the sheetin the formof aplaning surface comprisingalongitudinal frame member attached at ,its ends .to the opposite most distant longitudinal extremities of thesheet, a transverse memberattachediat its ends to the lateralextremities vof the sheet, said transverse member being disposed to the lee of the longitudinal member and translatablerearwardly relative to the longitudinal member when wind forces in flight urge the lateral extremities of the sheet rearwardly.

2. In a kite of the type described, a.flexible sheet of polygonal shape, .means for supporting the sheet in the form of a planing-surface comprising a continuous filamentary element extending about the periphery of the sheetand secured thereto, a longitudinal frame member attached at its ends to the filamentary element .at the opposite most distant longitudinal extremitiesof the sheet, a transverse member attached atlts ends to the vfilamentary element at the opposite lateral extremities of the sheet, said transverse memberbeing disposed to the lee of the .longitudinal member and translatable rearwardlyrelative to the longitudinal member when-windforces' in flight urge thelateral extremities.ofthesheet rearwardly.

3. In a kite of the type described, a poly onal flexible sheet, means for supporting the sheet .in the form of, a planing surface comprisingalongitudinal frame member attached atitsiendstotthe opposite most distant longitudinal extremities of the sheet, a portion of said longitudinal frame member having part of the sheet secured upon it to form a triangular keel converging from the base of said frame member upwardly and projecting forwardly of the planing surface of the sheet, a transverse member attached at its ends to the lateral extremities of the sheet, said transverse member being disposed to the lee of the longitudinal member and freely movable rearwardly relative to the longitudinal member.

4. In a kite of the type described, a flexible sheet of polygonal shape, means for supporting the sheet in the form of a planing surface comprising a, continuous filamentary element extending about the periphery of the sheet and secured thereto, a longitudinal frame member attached at its ends to the filamentary element at the opposite most distant longitudinal extremities of the sheet, a portion of said longitudinal frame member having part of the sheet secured upon it to form a triangular keel converging from the base of said frame member upwardly and projecting forwardly of the planing surface of the sheet, a transverse member attached at its ends to the filamentary element at the opposite lateral extremities of the sheet, said transverse member being disposed to the lee of the longitudinal member and freely movable rearwardly relative to the longitudinal member.

5. In a kite of the type described, a flexible polygonal sheet, a filamentary element extending about the edges of the sheet and secured therewith, means for supporting the sheet in the form of a planing surface comprising, a longitudinal frame member attached to the filamentary element at the opposite most distant longitudinal extremities of the sheet, a stiff transverse strut structure adapted to engage the filamentary element at the opposite lateral extremities of the sheet, with said transverse strut structure being disposed to the lee of the longitudinal member and freely movable rearwardly relative to the longitudinal member, said longitudinal frame member being a thin rigid vertical plate forming on its leading edge a contacting support for said flexible sheet throughout its length, and giving a pyramidoidal form to the planing surface of said sheet with the vertex of the pyramid located forward of the intersection of the longitudinal member and the transverse strut structure, a portion of said longitudinal frame member having part of the sheet secured upon it to form a triangular keel projecting forwardly of the planing surface of said sheet and extending from the base of said member to said vertex, said frame member being tapered in depth from said vertex to its uppermost longitudinal xtremity.

6. In a kite of the type described, a polygonal flexible sheet, a filamentary element extending about the edges of the sheet and secured therewith, means for supporting the sheet in the form of a planing surface comprising a longitudinal frame member attached at its ends to the filamentary element at the opposite most distant longitudinal extremities of the sheet, a lateral strut structure for the sheet comprising two stick extending transversely to the longitudinal member, one end of each stick being adapted to engage the filamentary element at the opposite lateral extremities of said sheet, stop members on opposite sides of said sticks, and means to hold said sticks in overlapped relationship through a portion of their length with the non-engaged end of each in abuttin position against the stop member of the other stick, said lateral strut structure being disposed to the lee of the longitudinal member and freely movable rearwardly relative to the longitudinal member.

EDWARD N. WINSLOW.

REFERENCES CITED The following references are of record in the file of this patent:

FOREIGN PATENTS Number Country Date 4,230 Great Britain 1907 444,153 France July 31, 1912 

